Walk the BIT and BCT to find the ODMDATA word in the
CustomerData field and put it into Scratch20 reg for
use by kernel, etc.

Built all Tegra builds OK; Booted on Seaboard and saw
ODMDATA in PMC scratch20 was the same as the value in my
burn-u-boot.sh file (0x300D8011). NOTE: All flash utilities
will have to specify the odmdata (nvflash --odmdata n) on
the command line or via a cfg file, or built in to their
BCT.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>